| Reaktanz | reactance |
| Reaktant | reactant |
| Reagenz | reagent reaction |
| Reaktion | reaction |
| Reaktor | reactor |
| reaktiv | reactive |
| Aktant | agent complement |
| rektal | rectal |
| Kreistanz | round dance |
| Rattan | rattan |
| Regentanz | rain dance |
| Rundtanz | round dance |
| Seiltanz | tightrope walking |
| Rasanz | terrific speed verve |
| Relevanz | relevance |
| Resonanz | resonance feedback |
| Vakanz | vacancy |
| Breakball | break point |
| Reading | Reading |
| Reaktionär | reactionary |
| reaktionär | reactionary |